This invention relates to the production of yarns, filaments, ribbons and the like from synthetic linear polymers and more particularly to improvements in the assembly from which such articles are spun.
It is customary to filter a synthetic filament forming composition before extruding it through a spinneret assembly which includes a holder filled with a filtering medium. One filtering medium which maintains a high degree of porosity under an applied load is a metal alloy such as disclosed by Phillips in U.S. Pat. No. 3,896,028. The alloy disclosed by Phillips which consists of 30 to 40% by weight chromium, 2 to 4% by weight silicon, minor amounts, at ordinary levels of carbon and nitrogen with the remainder being iron is a particulate filter medium in which the particles are irregularly shaped with a rough surface. While this material provides high levels of some of the properties of an ideal filter medium certain polymer additives in the polymer cause high pack blinding rates which in turn limit pack life.